1. Field of the Invention
The present invention relates to roofing systems, and, more particularly, to a formulated concrete slurry coat for eliminating the need of a base sheet roof membrane and mechanical fasteners in the installation of a roof membrane system to an underlying lightweight concrete deck on a roof structure.
2. Description of the Related Art
Generally, roof systems that use lightweight concrete, with or without insulation, require a base sheet membrane to be mechanically installed to the lightweight concrete for the purpose of allowing moisture to migrate. Once the base sheet is mechanically attached to the lightweight concrete, additional layers of roofing membrane are attached to the base sheet. The additional layers of roofing membrane may be attached by self adhesion, heat welding, or cold adhesive in order to bond the membranes together as a membrane system. Despite the widespread use of the mechanically attached base sheet membrane (using mechanical fasteners) in low sloped roof systems, there are significant drawbacks associated with its use. The increased amount of fasteners installed in order to meet the wind uplift requirements actually damages the lightweight concrete, particularly at the corners and perimeter of the roof. This can lead to roof deck failure. Furthermore, the use of mechanical fasteners damages the underlying concrete deck. More particularly, when the roof membrane system needs to be replaced, the existing roof membrane system must be removed, along with the base sheet and mechanical fasteners. Removing the mechanical fasteners results in the creation of large holes that are left in the lightweight concrete deck. When the new base sheet membrane is installed, new mechanical fasteners penetrate new areas of the existing lightweight concrete and, consequently further damage is caused to the lightweight concrete deck. While the use of lightweight concrete in lieu of insulation has the benefits of providing a slope for the roof system, as well as providing a lasting insulating structure for all future roof systems, the damage caused by mechanical fasteners requires costly and time consuming repairs when reroofing. In view of these shortcomings of the traditional mechanically attached base sheet membrane, there exists an urgent need in the roofing industry for an alternative method of installing a roof membrane system to an underlying lightweight insulating concrete deck on a roof structure that preserves the integrity of the lightweight concrete deck, while also reducing the cost of installation of the roof system.